proprioception: The normal physiological sense of your posture and the location of your limbs based on your sense of touch, space, etc. Proprioception is the reason you can close your eyes and touch your nose without poking yourself in the eye, walk down a stairway without staring at your feet, or eat soup without ending up with a face-full of hot chicken and noodles.
(With gratitude to the Dinosaur Comics.)